Nanoparticles have been of much interest in a variety of applications from solar cells to diagnostic medicines to transistors. While the commercial applications of oxide nanoparticles are prevalent, e.g., nano-titania and nano-silica in sunscreens and nano-iron oxide in biomedical imaging, metal nanoparticles and nanocrystals applications have lagged behind. One significant barrier to the wide-spread implementation of metal nanoparticles and nanocrystals has been the production of commercial-scale qualities with specific physical properties. This is especially true for nanocrystals as their applications often prefer, if not require, high uniformity (e.g., narrow size distributions and consistent shapes).
This high uniformity is difficult to achieve with the more prevalent synthesis routes like laser ablation, sputtering, and some wet-chemistry methods. While some wet-chemistry methods can meet the narrow size distribution requirement, the large volumes of chemicals, especially solvents, required to produce the nanoparticle and the longer synthesis time significantly increase the cost and environmental impact, which in turn hinders scale-up efforts.